In recent years, study of M2M (Machine-to-Machine) communication is progressing in which communication is executed between machines that are connected to a communication network without operation by a human so that proper control of machines and the like are automatically performed. For example, in 3GPP, standardization of a communication standard on M2M is progressing as a name of MTC (Machine Type Communication) (for example: non-patent document 1).
From now, it is predicted that M2M terminals and the like will become widespread at an accelerated pace. In a network accommodating these large amount of terminals, for example, since there is a possibility in that congestion may occur due to re-connection, caused by network apparatus failure or server failure or the like, that is simultaneously performed by the large amount of M2M terminals, necessity of congestion control different from that of general terminals is being discussed in standardization and the like.
As such a congestion control technique, in 3GPP, a technique is proposed in which, communication is classified into non-priority (low priority) and general (normal priority), and LAPI (Low Access Priority Indicator) which indicates non-priority is set to an M2M terminal that is positioned as non-priority, so as to perform congestion control based on the LAPI (for example, non-patent documents 2, 3 and the like). By introducing the LAPI, for example, congestion control becomes available in which, when congestion occurs, communications of general terminals are prioritized and only LAPI terminals are restricted.